Pre-infection of PBMC with ΔlspA resulted in significantly reduced HIV infectivity of isolated CD4+ T cells relative to those infected with wild-type M. bovis BCG (Fig 2, p = 0.013), although HIV infectivity of CD4+ T cells following PBMC infection with the mutant remained significantly higher than that observed following that with wild-type M. smegmatis (p<0.01). The gene discussed is CD4; the disease is infection.